Photographic developing machine automatic cutoff

ABSTRACT

In a machine for processing photographic film, a main switch in the main power supply to the machine is normally held in the closed position so that the machine runs. A timing circuit is reset each time film is fed into the machine. At a set time after the last film is fed into the machine, an electromagnetic solenoid opens the main switch to automatically cut off the machine.

United States Patent [151 3,647,124 Spicer 1 Mar. 7, 1972 [54] PHOTOGRAPHIC DEVELOPING 2,998,175 8/1961 Topping ..226/43 MACHINE AUTOMATIC CUTOFF 1,203,552 10/1916 Berry ....307/141.4 X 374,652 12/1887 Bosworth ....307/l4l.4 X [72] Inventor: Oliver V. Splcer, Lubbock, Tex.

A 2 R Primary Examiner-Allen N. Knowles [73] sslgnee Swain odgers a part interest Attorney-charles w. Coffee [22] Filed: Dec. 29, 1969 211 App]. No.: 888,716 [57] ABSTRACT In a machine for processing photographic film, a main switch in the main power supply to the machine is normally held in [52] 226/134 307/1414 the closed position so that the machine runs. A timing circuit [51] Int. ..B65h 25/32 is reset each time m is fed into the machine. At a set time [58] Field of Search ..226/43, 48, 46, 47, 134; after the last film is f d into h machine, an electromagnetic 318/446, 445; 307/ 141.4, 141 olenoid opens the main switch to automatically cut off the machine. [56] References Cited 2 Claims, 3 Drawing Figures UNITED STATES PATENTS t .8 t v.

I 2,944,104 W N35 "3::11-1.::xxlzntzrll flfli MAIN DRIVE. MOTOR 4. HEATER IHO'IOGRAPHIC DEVELOPING MACHINE AUTOMATIC CUTOFF BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photographic developing machines and more particularly to a device for automatically cutting off a machine at a fixed period of time after film is fed therein.

2. Description of the Prior Art At present time there are a large number of machines in use for automatically developing photographic film. These machines have a conveyor means for accurately conveying film through different reagent tanks to properly develop, fix, and dry, the film. It takes film about 7 minutes to be processed through such a machine. It is desirable to cut the machine off after the last film is processed to save wear and tear upon the machine. On the other hand it is imperative that the machine not be cut off while film is being processed because the film would delay too long in one reagent or the other, thus spoiling the film. With different people using the machine, it is almost impossible for any one person to shut the machine off after their film has been processed because someone else may have fed film into the machine and this film would still be in process. Some cutoffs on the market have a thermal circuit for this purpose. in these machines, an electrical element is heated by a short burst of current each time film is fed to the machine. Then the machine is cut off when the thermal element cools down. These thermal devices have not proved satisfactory because after several hours of use, they become extremely hot and instead of cooling off in 7% or 8 minutes, 30 minutes may be required.

SUMMARY OF THE INVENTION New and Different Functions My invention is to provide a positive cutoff, which has sufficient accuracy for the purpose and does not have accumulative delays therein. Specifically, machines upon which the automatic cutoff device is installed have a replenishing switch by which the reagent tanks are replenished each time the film is fed into the machine. The amount of reagent used to replenish the tanks varies according to the size of the film. By my invention, this replenisher switch is used to start a timer running for a predetermined period of time. Inasmuch as most machines require 7 minutes to process the film, the timer is conveniently set on 8 minutes. Therefore each time the replenisher switch is activated, this electrical impulse is used to restart the timing circuit.

The automatic cutoff switch to the main motoris a switch which is normally in the closed position, i.e., the contacts of this relay switch are spring biased so the switch is closed unless there is an electrical force which opens the switch.

This has some definite advantage. The circuit is fail-safe. I.e., if there should be a malfunction in the timing circuit or if the timing device should become unplugged or if any other mishap should occur, the machine remains in safe position. The safe position for the machine is for it to remain running. If the machine remains running, it must be manually turned off at the end of the workday and additional wear and tear upon the machine has occurred, which wear and tear is of small importance. However, the machine has not been improperly turned off during the processing of film. There has been nospoilage of film, which would be of major importance, because of malfunction of the timing device. Also, if the timing motor or other timing circuits malfunction and it is not necessary to disconnect them for repairs, it is not necessary to do any rewiring of the machine or to bypass the switch. The switches all remain in the normal run position. Any time the timing circuit is disconnected, the main machine continues to function properly with the timing circuits removed for repair or replacement.

This invention provides an automatic cutoff, which functions in a new and different manner.

Objects An object of this invention is to provide a fail-safe automatic cutoff for a photographic developing machine.

Another object is to provide a device which has the necessary accuracy.

Further objects are to achieve the above with a device that is sturdy, compact, lightweight, durable, simple, safe, versatile, efficient, and reliable, yet inexpensive and easy to manufacture, install, operate, and maintain.

Still further objects are to achieve the above with a method that is safe, rapid, versatile, efficient, and inexpensive, and does not require skilled people to install, adjust, operate, and maintain.

The specific nature of the invention, as well as other ob jects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not necessarily to the same scale.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic representation of the electrical circuits for a first embodiment of this invention, using an electric clock type timer.

FIG. 2 is a schematic representation of the electrical circuits for a second embodiment of this invention, using a capacitorcharging timing device.

FIG. 3 is a schematic representation of this invention showi'ng a generic timer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment No. 1

Referring to the drawing at FIG. 1, a photographic development machine includes rollers 10, which represent means for conveying film through the reagent tanks (not shown). The rollers 10 are driven by main drive motor 12. Also, it is neces sary to keep the different reagent tanks at a fixed temperature;

therefore, heater 14 is provided for this purpose. Furthermore it is necessary to replenish the reagents within the tanks and therefore, replenisher 22 has been schematically illustrated.

It is emphasized that the drawing only schematically represents the machine. There is a source of power 16 with two bus bars 18 and 20 with all of the circuits receiving their power between bus bars 18 and 20. However, some of the motors might be direct current motors with rectifiers and other motors might operate on different voltages, and there would be various transformers for the different parts; all of this is within the skill of ordinary craftsmen; therefore, a schematic representation has been made of the equipment to show all equipment being connected between the two bus bars 18 and 20. For an example, the heater 14 is shown as attached by manual switch 24 so that the heater 14 with its switch 24 is attached in series from the bus bars 18 to bus bar 20. It will be understood that the main power supply 16 could itself be on an automatic timing circuit controlled by the time of day. l.e., it would be turned on. at 5:00 oclock in the morning and turned off at 7:00 oclock at night.

The main drive motor 12, connected to the rolls 10 by a transmission system shown only by dotted line 26 in the drawings, is illustrated electrically connected in series with manual switch 28 and automatic cutoff or main switch 32. The replenisher 22 is connected in series with manual replenisher switch 30. In many of the commercial models, the manual switch 30 is in the form of a time switch so that according to two of which, 136 and 138, are power terminals. These are represented in the drawing as connected to bus bars 18 and 20, although it will be understood that the power to the automatic cutoff 134 could be received from any conventional source and not necessarily from the same power source 16 as the photographic developing machine. Another of the five terminals is terminal 140 by which the automatic cutofi device 134 receives its information or signal that film has been started through the machine. Inasmuch as the replenisher 22 will be activated each time film is started through the machine, the terminal 140 is conveniently connected to the wiring of the replenisher circuit so each time the manual switch 30 is closed, the automatic cutoff device 134 will receive the signal through the terminal 140 that new work is beginning. The other two terminals are terminal 142 and 144, which are the terminals by which the cutoff switch 32 is connected into the main power supply to the main drive motor 12.

Relay coil or solenoid coil 146 is connected in series from input terminal 140 to power terminal 138. Therefore, each time film is added to the machine and replenisher switch 30 is actuated, there will be an electromagnetic pulse flowing from the input coil 146. This input coil 146 energy output will, in due time, result in output energy from output relay coil or output solenoid coil 148. If fuse 152 in the power supply to the automatic cutoff 134 were open or if manual switch 154 were open to the cutoff device, there would be no power to the output coil 148. If there is no power to the output coil 148, it will not produce output power; therefore, the automatic cutoff switch 32 will remain closed and the main drive motor 12 will remain running. Loss of power to the automatic cutoff device will always leave the mechanism in safe position with the main drive motor of the photographic development machine in the operating position. Also, the entire timer 150 can be removed for repairs or replacement and this removal of the timer will leave the photographic development machine in operating condition.

Looking specifically at the timer 150 illustrated in FIG. 1, input switch 160 will be opened each time the input coil 146 is energized. The input switch 160 is in a normally closed position and is opened only upon energization of coil 146. When the switch 160 is open, it removes power from electromagnetic clutch 162. This removal of power from the clutch 162 causes the clutch to relax, which allows the clock 164 to reset and resume timing. The clock 164 will reset to the time determined (example: 8 minutes) each time the clutch 162 relaxes. When the clock is timing or set for any positive time, clock switch 166 is connected so that power is transmitted from input switch 160 through the clock 164 to the power terminal 138. Also, the clock switch 166 is constructed so that when the clock runs to zero time, the clock switch 166 will move to contact 168, which is connected to output coil 148. Therefore, when the clock reaches zero, there will be a complete power circuit from bus bar 18, terminal 136, fuse 152, manual cutoff switch 154, input switch 160, clock switch 166, contact 168, output coil 148, power terminal 138 and back to bus bar 20. When this circuit is complete, the automatic cutoff switch 32 is open and therefore, the main drive motor 12 is stopped. Also, if there is any break in the circuit anywhere (e.g., by the fuse 52 or by the disconnection of the entire timer or the disconnection of the entire automatic cutoff device) the output coil 148 will not be energized and the cutoff switch 32 will remain closed, leaving the main drive motor 12 running and thereby driving the rollers forming conveying means for conveying film through the machine.

The term control circuit is used to include fuse 152, switch 154, switch 160, clock or timing switch 166, contact 168, and output coil 148.

The clock 164 with its clutch 162, clock switch 166 and connection 168 are available commercially on the market as a unit. These timer units are available from different companies and are commercial items; therefore, they will not be described in detail any further except to state that when no power is supplied to clutch 162, the clock resets to a positive time and the clock switch 166 provides power to the clock. When the clock reaches zero, the timing switch of clock switch 166 moves and supplies power to terminal 168 and does not continue to provide power to the clock 164.

The time to which the clock can be set is conventionally provided by a dial on the face of the clock; therefore. the running time can be set from 1 to 30 minutes. If it is desired to leave the machine running an additional 5 minutes after the last work has been completed, the clock could be set at 12 minutes. Each time a film is fed in, it runs for 7 minutes until the film is completed and then an additional 5 minutes after completion of the film.

When additional film is fed and there is an additional energization of the input coil 146, the opening of the input switch 160 also prevents any current from going to the put-put coil 148; therefore, there is no cutoff of the machine.

Embodiment No. 2

FIG. 2 illustrates a second embodiment, which also controls a photographic developing machine having conveyor rolls 10 driven by mechanical transmission 26 from main drive motor 12, normally connected by manual switch 28 between bus bars 18 and 20, which are provided power from main power source 16. Likewise, heater switch 24 connects power to the heater 14. The manual replenisher switch 30 is periodically manually operated to actuate the replenisher 22. Automatic cutoff circuit 234 contains main power switch or automatic cutoff switch 32, which is contained in a separate unit having five terminals: power terminals 236 and 238, input terminal 240 connecting to input coil 246, and the output terminals 242 and 244 connecting the cutoff switch 32. Output coil 248 in the control circuit provides a continual electromagnetic force to open the switch 32 at a preset time after the last electromagnetic pulse is produced by the input coil 246. Fuse 252 and switch 254 connect terminal 236 to timer 250, which is different from the timer 150 of the first embodiment.

1n the timer 250, rectifier 272 is connected to the manual switch 254 and supplies direct current to capacitor 262, which is connected to terminal 238 and thus bus bar 20 through rheostat 264 and timing relay coil 270. Therefore, if the switch 260 which shunts capacitor 262 is open, the capacitor 262 will be charged in a predetermined time through the variable resistance of the rheostat 264. The switch 260 is normally open and is closed each time the input coil 246 is energized responsive to the closing of the replenisher switch 30. This short circuits the capacitor 262 thereby discharging same.

The timing switch 266 is spring biased in the closed position. However, the current through the timing coil 270 will hold the switch 266 open. When the timing switch 266 is closed, the control circuit will be complete from bus bar 18 through power terminal 236, fuse 252, switch 254, contact 268, switch 266, output coil 248, terminal 238 to bus bar 120.

When there is a completed circuit in this manner, the automatic cutoff switch 32 will be opened by the output coil 248.

and the main drive motor 12 will be cut off, thereby stopping the conveyor means of the photographic machine represented by the rolls 10. Of course stopping the rolls 10 reduces the wear and tear thereon. Therefore, it may be seen that l have provided a timer means 250 which supplies current to the output coil 248 a set time after the last impulse signal has been received on coil 246.

Embodiment No. 3

FIG. 3 illustrates a generic embodiment for the control of a photographic developing machine having conveyor rolls 10 driven by mechanical transmission 26 and main drive motor 12, which is normally connected by manual switch 28 between bus bars 18 and 20, themselves, provided by power from main power source 16. As in the previous embodiments, manual heater switch 24 connects power to heater 14. The manual replenisher switch 30 is periodically manually operated to actuate the replenisher circuit 22, which is connected between the bus bars 18 and 20.

Automatic cutoff circuit 334 contains automatic cutoff switch 32. The cutoff circuits are contained in a separate unit,

it having five terminals; power terminals 336 and 338, input terminal 340 connected to input coil 346, and output terminals 342 and 344 connecting the cutoff switch 32. Output coil 348 provides a continual electromagnetic force to open the switch 32 at a preset time after the last electromagnetic pulse is produced by the input coil 346. Fuse 352 and switch 354 connect terminals 336 to timer 350. Switch 366 connects from the switch 354 to contact 368 and the output coil 348 being the control circuit. The timer 350 is a self-contained unit in itself, and in this illustration, it is shown blank, except for the switch 366, to emphasize that there are several different timing circuits which could be used. The previous two embodiments have illustrated and described two specific embodiments of the timer, but it is emphasized that there are various types of timers which could be used to duplicate the whole art of horology and can be either mechanical, pneumatic or electrical in nature.

I regard my invention as having the motor normally operating unless it is positively disconnected by the automatic cutoff device, which in itself is actuated responsive to the timer which is activated for a fixed period of time after the last input of film into the machine.

The embodiments shown and described above are only exemplary. I do not claim to have invented all the parts, elements or steps described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific examples above do not point out what an infringement of this patent would be, but are to enable the reader to make and use the invention.

l claim as my invention:

1. In a machine having a. conveyor means for moving work material through the machine in a processing cycle time,

b. at least one electric drive motor, drivingly connected to said conveyor means, 1

c. a main power line connected to the electric drive motor for supplying electric power to all conveyor means, and

d. a manual main power switch in the powerline;

e. the improved structure for disconnecting the drive motor to automatically turn off the machine comprising in combination with the above:

f. a timing device,

g. an electric control circuit,

h. a timing switch in the control circuit,

j. means. connected to said timing device for opening the timing switch at all times the timing device is timing,

' k. an automatic cutoff switch in series with said manual main power switch,

I. an electromagnetic coil in the control circuit for opening the automatic cutoff switch when the control circuit is energized by the closing of the timing switch, and

m. means for restarting the timing device each time new work material is fed to the machine,

n. said structure for disconnecting the drive motor comprising a unitary integral unit.

2. The invention as defined in claim 1 wherein said means for restarting includes 0. an input coil, and

p. signal means for feeding a pulse of electricity to the input coil each time new work is fed into the machine. 

1. In a machine having a. conveyor means for moving work material through the machine in a processing cycle time, b. at least one electric drive motor, drivingly connected to said conveyor means, c. a main power line connected to the electric drive motor for supplying electric power to all conveyor means, and d. a manual main power switch in the powerline; e. the improved structure for disconnecting the drive motor to automatically turn off the machine comprising in combination with the above: f. a timing device, g. an electric control circuit, h. a timing switch in the control circuit, j. means connected to said timing device for opening the timing switch at all times the timing device is timinG, k. an automatic cutoff switch in series with said manual main power switch, l. an electromagnetic coil in the control circuit for opening the automatic cutoff switch when the control circuit is energized by the closing of the timing switch, and m. means for restarting the timing device each time new work material is fed to the machine, n. said structure for disconnecting the drive motor comprising a unitary integral unit.
 2. The invention as defined in claim 1 wherein said means for restarting includes o. an input coil, and p. signal means for feeding a pulse of electricity to the input coil each time new work is fed into the machine. 